The foreseeable future of mankind is a digital future and it is indisputable that one of its attributes will be Blockchain technology, which is the subject of this article by the authors of the NEC2020 Concept, which provides an original description of the technology in a popular presentation.
Blockchain (chain of Blocks) - this term defines a computer database, organized and filled in a certain way, through an associated sequence of Blocks. The block is the main element of the Blockchain, which hosts and stores data. Each Block is unique and occupies the same place between two other Blocks. All Blocks are lined up in a chronological chain, which has the first Block and the last, followed by the next newly created Block. The hardware and software for creating Blocks and placing them on the Blockchain is provided by the Blockchain Miners. Also, each of the Miners stores a replica of the Blockchain on their computer.
Despite the fact that Blockchain is perceived, first of all, as a technology that provided the emergence and existence of such a complex phenomenon as Cryptocurrency, there is nothing difficult to understand the organization of adding and storing information accepted in the Blockchain. Imagine a caravan where every camel (except the first) is tied to the camel walking in front, then the camel is the Block, and the rope is the connection of the Blocks.
To understand Blockchain as a technology, you need to get an understanding of what hash is. We point out right away that the Hash, as a result of hashing, just binds the Blocks together. In the caravan example, this is the rope that ties one camel to another. True, each rope is unique and is part of the camel, which makes it unique itself.
Before proceeding, one should gain an understanding of digital information. Without going into the definition of what information is, let's go from the opposite, we will consider information as everything that can be digitized, that is, encoded for transmission, processing, storage and subsequent decoding. Again, let's take an example, so a piece of music is information, notes are the code of a given piece. Musical works can be represented in another code - digital, which is understandable for devices that use such a code in their work. We use such devices, in general, every day.
Hash is a key concept in cryptography. The word itself can mean, depending on the context, two things: a hashing function or the result of such a function. Hashing is the execution (in the classical sense) of a cryptographic algorithm for processing a digital object in order to obtain its Hash - a unique digital code of a certain size. Hashing, as a hash function, is a mathematical algorithm that takes as input any array of data (text, picture, binary code, etc.) of arbitrary size and generates from it a sequence of, for example, letters and numbers, of a fixed length. Hashing is represented as folding the data into a unique calculated Hash. The reason for the appearance and existence of a Hash is the ability to operate on data of a certain size, which uniquely correspond to an object.
To understand what hash and hashing are, consider its implementation using the following example. Let's take two dozen text files of different content and size. Each word in each text of each document is represented as a number that corresponds to the number of characters in a word. We add up all the numbers on each page and multiply each result obtained by the 12th Fibonacci number (from the Fibonacci number series), from each obtained value we will leave the first 32 digits, this will be a unique Hash for each of the twenty documents. In practice, the algorithms are more complicated, and the probability of getting the same Hash tends to zero. In any case, the algorithms used today do not allow creating the same Hash until the end of life, for example, the solar system, and even the life of the Blockchain itself, even more so.
In the above example, Hash uniquely identifies the document and its content. Practical use of hashing allows you to solve many problems in the modern digital world. For example, copyright protection. Let's assume that the information about each work, after its digitization and hashing, is placed in a public database. If the attacker wants, for example, to offer "his" book to the publisher, he receives the hash of the text of the work and verifies it with the hashes in the database and refuses the "author". In fact, this will not give protection of authorship, since an attacker only needs to remove one letter from the text and his hash will become completely different. But for immutable objects, such use of Hash is very relevant and useful.
How it works by example. One person makes a request to a friend who is going on a trip to transfer a package to his relative in another city and receive a reward from him. During the journey, the passenger carefully opens the package and discovers a letter and money in it. The text of the letter contains an indication of the amount that was sent in the package. There is a sequence of numbers at the end of the letter. The acquaintance turns out to be a thief, and rewrites the letter exactly, but indicates a lower amount, and leaves the difference to himself. A relative opens the package, reads the letter and recounts the amount, the messenger does not worry and waits for his fee. A relative asks him to wait, digitizes the text of the letter using an algorithm similar to that used by his relative. Checking his result and the number at the end of the letter, he informs the messenger that he is a thief.
This example shows how, in practice, you can use the Hash to determine the reliability of the information received. Using the Hash function, a Hash of the object is created by various communication channels, the object itself and its Hash are sent to the addressee. The addressee, using a similar Hash function, creates a Hash of the received object and compares its Hash with the Hash received from the sender, they must match.
Now let's take an example that is closer to understanding Blockchain. The so-called data chain - a linearly organized sequence of information, existed always and wherever it was convenient. A good example of Blockchain is a calendar or an ordinary book, in the modern world, it is already necessary to add paper. If we take the book for the Blockchain, then the text on each page is a Block, which has its own unique identifier - the page number. Thus, all pages are linked in a chain with a certain sequence, through numbering. If we specify the Hash of the previous page of this book instead of the page number, we get the Blockchain. To understand the logic of the Blockchain, it should be indicated that the Hash of the previous page includes all of its content, including the required Hash of the previous page. That is, the hashing object is the text of the page itself + the Hash of the previous page.
Moving a Block in the Blockchain to another place is also impossible, as well as a page in a book, since there are rules accepted and followed by all and the meaning of their execution. It is also impossible to replace the Block with another, but in our example, insert instead of the original page, a page from another book, which (book) has a different title, author, year of writing, year of publication, the publishing house itself, circulation, date of signing in circulation, cost, format, language, etc. The example with the book gives an understanding of the reason for this impossibility, since the "number" of the Block is encrypted by a certain complex cryptographic algorithm and is so unique that the Block entering the chain with the same "number" can occur on a day that is so remote from today that the Blockchain itself there will no longer be, there will be no people on Earth, and the Earth itself, and the Sun. In addition, in order to integrate a fake Block, it is necessary to change its identification in the previous and in the next Block, that is, to replace them, and, accordingly, all others, which is impossible by definition, since it will be a different Blockchain.
Now let's look at a blockchain with hashing on the example of a multivolume publication of an endless work - the chronicle of mankind. One year of history, that's one Volume. One Tom is one Block. The processed content of the Block is its Hash, which is the name of this Block, and the volume, respectively. At the beginning of the text, each Volume has the Hash of the previous Volume. The end of the current year will end with the creation of the next Volume in the history of mankind, the generation of its Hash and the placement of the Tom-Block in the chronological sequence of the history of man on Earth.
The above gives an understanding of what a Hash is and how data is organized in the Blockchain. Classic Blockchain Cryptocurrency requires the presence of Miners to ensure its existence, through confirmation of the content of the Blocks and their placement in the chain. Let's return to the example, when a book acts as a Block, in which pages are records made by Blockchain users and ask miners to fix their records in this Block FOREVER for a reward.
Each of the Miners is a software and hardware complex controlled by a conventionally human, and each such Miner receives an offer to check and include the Block in the Blockchain. Each Block has a cost, which depends on several parameters, but it exists and is announced to all Miners. The Miner's activity is quite costly work and therefore each of them makes an independent decision whether to take a Block into work or not, focusing primarily on the amount of the proposed remuneration. The Block accepted by one miner for work, it is checked for compliance and reliability, is certified and sent to ALL other Miners for confirmation. If all other Miners have confirmed the truth of this Block, it is included in the chain and takes its place in it forever.
Let's go back to the book example. Imagine that identical copies of new books are sent to each library, each librarian chooses one of his set, reads, decides that this book can be used to replenish the library fund of each library, and informs other librarians of their decision, who are OBLIGED to confirm or refute such a decision. ... If the decision is made by everyone, the books from each set are sent by librarians to the shelves in each library, information about the book is entered in the same register for everyone, and the librarian who ensured the appearance of the book in all libraries received a reward for the work performed, for example from the author. A miner is like a librarian who is only concerned with staffing the library and only with good books.
Blockchain technology - provides for a peer-to-peer computer network, that is, one in which there is neither master nor subordinate element, where everyone who ensures the existence and functioning of the computer network is equal. A comparison with a huge store, where there is no one more important than the seller, and no other staff at all, is appropriate here. Now let's imagine that the record in the Block is a sales receipt. At the end of the business day, each salesperson compiles a Block of all their receipts and sends a copy of their Block to all other salespeople in the store. The rest of the sellers, in turn, do the same with their checks. Thus, each of the sellers stores and has at its disposal, duplicates of all conducted and documented transactions for the day from all sellers. And if a seller suddenly appears, who, while calculating the proceeds, discovered a lack of money, and decided to delete one check from his Block to cover the shortage, it is easy to find it when summing up the total revenue of the store. All sellers take out his Block and check his statement for validity, that is, they compare the content of his report (Block) and the amount received from him. It is also easy to check the appearance of a false seller, who reports the existence of "his" Block in the Blockchain, trying to achieve some of his own mercantile goal.
The combination of the specified features of the Blockchain provides a unique opportunity to use this technology in various spheres of human activity. The data placed on the Blockchain cannot be deleted, replaced and lost, since the Blockchain user cannot "negotiate" with all the Miners and even determine how many and where they are located. Another remarkable feature of the Blockchain is that the data posted on the Blockchain is always available and open, that is, there is no way to hide or deceive anything.
Blockchain has a unique, today, combination of features of its existence: independence, openness, reliability, availability. Nobody pays for the existence of the Blockchain, it exists for each of the Miners and at their expense, which is filled with rewards from users. A set of Blockchain algorithms allows you to ensure the presence of reliable information from its users, where each of them does not trust anyone and everyone at once. Also, Miners do not trust each other, who check themselves and everyone, but only for the purpose of the flawless existence of the Blockchain.
The uniqueness of the digital blockchain is that it can accommodate everything that can be digitized in its Blocks, so Blockchains definitely have a great future. So, at present, on cryptocurrency Blockchains, it is possible to place so-called Smart Contracts, in which the prescribed conditions are unchanged for the reasons stated above.
This article describes a Blockchain that works and has already proven itself, but is one of the possible options. The movement is moving not only towards the use of this technology, but also its optimization, as well as the search and creation of new technologies for the safe storage and use of information.
Article in ORIGINAL language HERE